Despite critical geochemical roles of microorganisms in biosphere maintenance, knowledge of microorganisms as they function in soils, sediments, and waters is limited. Constraints on knowledge are caused largely by methodologies that do not contend well with the complexity of field sites, with the scale differential between microorganisms and humans, and with artifacts that may a rise in characterizing microorganisms using laboratory-based physiological, biochemical, genetic, and molecular biological assays. A paradigm describing how knowledge is obtained in environmental microbiology suggests that the constraints on knowledge will yield to relationships developing between methodological innovations and their iterative application to naturally occurring microorganisms in field sites.